The present invention is related to compensated driver, and more particularly to approaches for providing compensated constant drive driver with minimal glitching.
Semiconductor devices typically include one or more internal functional blocks and one or more drivers. The internal functional blocks are designed to perform a particular function and to provide the results of the function external to the semiconductor device via the driver. Such semiconductor devices are often employed in environments where one or more of the supply voltage or temperature varies. Even with such variance, a driver buffer may be expected to maintain a reasonably constant drive impedance independent of the aforementioned variations. Further, the drive impedance may be maintained reasonably constant across different devices where the process values may vary substantially from one device to another. Maintaining this constant impedance assures a reasonable match between the driver buffer and the effective impedance of board traces modeled as transmission lines, and thereby reduces the reflections due to impedance mismatch. Reducing the impedance mismatch is helpful in maintaining signal integrity.
In some cases, maintaining constant drive impedance is achieved by modifying the effective width of the final stage drive transistors on the semiconductor device. Such an approach provides a reasonable approach to maintaining constant impedance, however, such an approach of increasing or decreasing the width of a drives stage has proven problematic for one or more reasons.
Thus, for at least the aforementioned reasons, there exists a need in the art for advanced systems and devices for providing drivers.